title: ["Oligocone" trichromasy, a rare form of incomplete achromatopsia].
abstract: METHODS
  An 11-year-old girl presented because of reduced visual acuity while color vision was almost normal. Besides a general ophthalmological examination, special psychophysical tests, such as perimetry, color vision tests using pseudoisochromatic plates, arrangement tests, the Nagel anomaloscope and spectral sensitivity measurement, and electrophysiological tests (electroretinogram and electrooculogram) were conducted.
  
  
  RESULTS
  The tests yielded the following: congenital nystagm, normal results at ophthalmoscopy, best visual acuity of 0.1 monocular and 0.2 binocular. Perimetry revealed a relatively central scotoma. All color vision tests showed only mild dysfunction of the blue-sensitive cones. Findings at photopic electroretinogram were almost completely lacking. There was no sign of progression in the last 6 years.
  
  
  CONCLUSIONS
  Differential diagnosis includes all diseases associated with congenital nystagm, such as aniridia, diseases of the optic nerve, albinism and all forms of hereditary cone dysfunction, cone dystrophies and complete and incomplete congenital stationary monochromatism. In the present case the findings are most congruent with oligocone trichromasy.
authors.affiliation: Augenklinik der Otto-von-Guericke-Universität Magdeburg.
authors.forename: P
authors.initials: P
authors.lastname: Ehlich
authors.forename: B
authors.initials: B
authors.lastname: Sadowski
authors.forename: E
authors.initials: E
authors.lastname: Zrenner
mesh_terms: D002648:Child; D003119:Color Perception Tests; D003117:Color Vision Defects / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D009759:Nystagmus, Pathologic / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology; D017949:Retinal Cone Photoreceptor Cells / Q000002:abnormalities* / Q000503:physiopathology; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests
vernacular_title: Die "Oligocone"-Trichromasie, eine Sonderform der inkompletten Achromatopsie.